There are a wide variety of terminals used in electrical connectors for terminating the ends of electrical wires. Some terminals are of the crimping type for clamping onto an exposed conductor of an electrical wire. Other terminals are of the insulation displacement or piercing type which cut through the surrounding insulating sleeve of an electrical wire to establish conductivity with the center conductor core. Many such terminals of either type are unitarily fabricated of stamped and formed metal material.
A common form of a one-piece stamped and formed electrical terminal for making permanent electrical contact with the conductor core of an insulated electrical wire is configured generally with a U-shaped cross section. The cross section defines a bottom wall of the terminal and opposite side walls to provide a channel for the electrical wire. Opposed portions of the side walls are used for crimping inwardly onto the insulating sleeve of the wire to provide a strain relief means therefor. Insulation displacement sections of the terminal are formed either out of the side walls or the bottom wall of the terminal to define notches or slots having widths slightly smaller than the conductor core to establish a good electrical contact therewith, the sides of the notches or slits cutting through the insulating sleeve which surrounds the conductor core.
When using electrical terminals of the character described above, there are not many problems with small or fine electrical wires in regard to the wires backing out of the insulation displacement sections of the terminals, as long as some form of crimping means is provided for holding the wire in the channel of the terminal. Small wires simply bend in response to extraneous forces. However, when using "power cables" or large electrical wires, such as 18 gauge wires on the order of 0.078 inch diameter, problems in establishing a good connection with a stamped and formed terminal often arise. For instance, because of the heavy gauge of a power electrical wire, such as used in computer harnesses, the wires tend to pivot about the insulation displacement sections of the terminal rather than bending as with a smaller wire. For instance, if an insulation displacement section is disposed at the rearmost area of the termination portion of the terminal, the stiff wire tends to pivot about that section, particularly during handling, with a tendency of the wire to move out of the insulation displacement section.
Consequently, there has been a tendency to form terminals of the character described with at least a pair of insulation displacement sections for redundancy purposes to insure that a good contact is established with the conductor core of a heavy electrical wire. However, problems have been encountered in providing proper strain relief for the wires because they have a tendency to walk out of the forward-most insulation displacement section, in addition to pivoting about the rear most insulation displacement section.
This invention is directed to solving these problems by providing a stamped and formed electrical terminal with redundant insulation displacement sections and improved strain relief means operatively associated with each section.